Racket for lawn-tennis and similar games



April 23, 1963 J. R. LACOSTE RACKET FOR LAWN-TENNIS AND SIMILAR emsFiled March 20, 1961 5 Sheets-Sheet 1 J. R. LACOSTE RACKET FORLAWN-TENNIS AND SIMILAR GAMES April 23, 1963 3 Sheets-Sheet 2 FiledMarch 20, 1961 .LMVEMTML mw wzw A ril 23, 1963 J. R. LACOSTE RACKET FORLAWN-TENNIS AND SIMILAR GAMES 3 Sheets-Sheet 3 Filed March 20, 1961Int/e m M 9 ,Z M Wm M, Z 7M+ Mid iid 15/ 67;

United States Patent Office ifi hfll'i Patented Apr. 23, 1963 s,0ss,777RACKET non LAWN-TENNIS AND snvnran names In the construction of racketsfor lawn-tennis and similar games, it has previously been suggested toconstruct the racket frames from metal channel elements or metal tubingof round or oval cross section in place of the conventional woodenframes. However, known rackets of this kind have not been successful.

A satisfactory tennis racket should be lightweight and well balanced.Its frame, while being as far as possible stream-lined in contourparallel to the direction of racket movement when striking a ball,should at the same time possess high resistance to twisting and warpingstresses as may arise when a ball strikes the racket off center.Further, it is necessary that the strings be attached to the framethrough simple and eifective means, preferably with a conventionalstringing machine; nor should the strings engage any sharp angles on theframe surface or be subjected to sharp bends since their service lifewould otherwise be reduced. Moreover the racket should not vibrate or benoisy in use.

It is an object of this invention to provide a racket which will fulfillthe above requirements to a high degree.

According to this invention, the racket frame is con structed from asectional metal element which comprises two spaced beads interconnectedby a web of smaller transverse dimension so as to define a pair oflongitudinal grooves between the beads along the opposite sides of theelement.

Preferably the metallic frame element is tubular; and one convenientmethod of producing such a tubular frame element is to deform a tube ofcircular or oval cross section by exerting pressure along twodiametrically opposite generatrices thereof; such deforming pressure maybe applied far enough to cause the opposite wall surfaces of the tube toengage each other, or alternatively a predetermined spacing may beallowed to remain between said opposite wall surfaces.

In making a racket frame from such a sectional metal element, theelement is bent in such a place that the aforementioned beads projectfrom opposite sides of the general plane of the frame.

A racket frame thus constructed combines light Weight and strength. Itsrigidity in the striking direction is very high even when provided witha low thickness dimension in said direction, so that the dragcharacteristic of the racket is low.

Such a racket frame can be assembled with a handle made of metal, woodor other material, and such assembly can readily be eifected in such away as to impart excellent resistance against torsional deformations tothe racket as a whole.

The stringing of such a racket can be carried out in various ways. Thusthe conventional method of threading the strings through spaced holesformed in the frame member may be used, such holes in this case beingformed through the web portion of the frame member. Alternativelyauxiliary means of attachment may be used for connecting the stringswith the frame and in this respect the provision of the outer and innerlongitudinal grooves in the frame considerably facilitates thepositioning of strings and exerts both a guiding and a protectingfunction therefor.

The ensuing disclosure made with reference to the accompanying drawings,given by way of example but not of limitation, will provide a clearunderstanding of the manner in which the invention may be embodied inpractice.

FIG. 1 is a simplified view of an improved tennis racket in frontelevation;

FIGS. 2 and 3 show two alternative forms for the sectional contour ofthe improved racket frame member;

FIG. 4 is a partial perspective View, on an enlarged scale, illustratingthe core of the racket and showing one example of the means forconnecting the frame with the handle;

FIG. 5 is a partial front view illustrating a modified form of handleassembly;

FIG. 6 is a section on line VIVI of FIG. 5;

FIG. 7 shows in cross section a perforated racket frame member providedwith eyelets for string attachment;

FIG. 8 is a section on line VIII-VIII of FIG. 7;

FIG. 9 is a fragmentary perspective view of a portion of the frameprovided with a stringing jig or template for defining the pitch of ahelix or coil used in the stringing process;

FIG. 10 is a sectional view on a plane parallel to the plane ofprojection of FIG. 9 showing the manner in which the strings are engagedaround the coil;

FIG. 11 illustrates a serrated wire annulus positioned within the framefor string attachment;

FiG. 12. is a partial longitudinal section showing means for retainingthe annulus with the strings attached thereto Within the frame;

FIG. 13 is a perspective view illustrating some modified methods ofwinding the string attaching wire; and

FIGS. 14 to 17 illustrate various ways of mounting the strings on ringsthreaded around the frame member.

Shown in FIG. 1 is a tennis racket wherein the frame is constructed froma sectional member 1 of special configuration to be described, bent tothe requisite shape of a loop, and further provided in this example withan arcuate bracing segment 2 for completing the oval frame. The framethus constructed is connected to a handle 3 and is provided with strings4 stretched across it.

The sectional member from which the frame is formed includes twolongitudinal beads 5 of preferably rounded form and interconnected by aweb portion 6 of lesser thickness so as to define a pair of grooves 7and 8 on either side of the member. Preferably the member is tubular. Itcan readily be formed to the desired cross sectional contour by using atube of any suitable e.g. circular or oval cross section and deformingit by applying pressure along two opposed generatrices of it, e.g. bypassing the tubular member through the nip between two rollers ofcorresponding contour, in one or more passes.

The width and depth dimensions of the grooves 7 and 8 may be variedaccording to requirements. When using a tubular member as indicatedabove, the sectional shaping operation may be so effected as to bringthe opposite wall portions of the member into engagement in the webportion, as shown in FIG. 2; alternatively a space may be left betweensaid wall portions as shown in FIG. 3.

In forming the frame, the contoured member is bent in such a plane thatthe beads 5 will be positioned, on opposite sides from the generalmid-plane of the frame, the trace of which mid-plane on the plane ofPEG. 2 is shown by the dotted line P.

The brace member 2 consists of a length of the same (or a similar)contoured member as that from which the main part of the frame is made.This brace is firmly secured to the main frame part preferably bywelding or brazing. Its positioning and assembly are greatly simplifiedsince, as shown in FIG. 4, with the ends lo cut so as to conform withthe shape of the contoured member 1,

the respective bead portions in the main frame member and the brace willprovide dual guiding means to permit highly accurate relative centering.

A racket frame constructed as thus described has excellent rigidityinthe direction of movement when hitting a ball, while being contouredin said direction for minimum air resistance or drag, and at the sametime showing.

satisfactory resiliency in the direction of the plane defined by thestrings. These features are due to the fact that the cross sectionalcontour of the frame member according to the invention possesses a highmoment of inertia referred to the trace of plan P while having arelatively small thickness dimension parallel to that plane.

Tests carried out with racket frames of this type made from hardenedalloy steel provided with a hard chromium plating have yieldedespecially satisfactory results.

The frame may be connected with the handle in any of various ways.Excellent assemblies have been obtained by providing the racket framewith adjacent spaced extensions 9 of the contoured frame member 1 asshown e.g. in FIGS. 1, 4 and 5, and inserting the end portions of suchextensions into slots formed in a core member 11 made of wood or thelike, then radially reinforcing the assembly by inserting it into anannular ferrule member 12; the ring or ferrule member 12 may, ifdesired, form anintegral part of a tubular handle 3 (FIG. 4). Therecesses10 and the appropriate faces of the ring member may be shaped toconform with the contour of the frame member including the grooves 7 and8 thereof; however a very strong assembly is found to be obtained evenwhen the recesses 10 and ring member 12 are so formed as to engage onlythebead surfaces of the frame member.

In view of the highly rigid character of extensions 9, itmay in manycases be found sufficient merely to insert the core member 11 in betweensaid extensions, and bond it thereto if desired. In this modified formthe ferrule member 12 would be dispensed with; furthermore, the core 11may then form an integral extension of the racket. handle.

In another modification, shown in FIGS. 5 and 6, the extensions 9 may beinserted into the suitably shaped end portion 13 of a tubular rackethandle 3, and the assembly then being preferably welded or brazed.

Regardless of the particular form of frame-to-handle assembly'used, anextremely strong connection therebetween is obtainable. The resultingracket assembly is found in particular to show remarkably highresistance against twisting stresses, an important feature for a tennisracket. Further, a good balancing of the racket assembly can beachieved, since the high rigidity and strength ofthe sectional elementfrom which is formed the upper portion of. the handle adjacent theframe, makes it possible so to-construct the assembly that most of theweight of it is located at the frame and at the grip, a feature that isfound to improve the effectiveness of the racket.

All the above favourable features are obtainable Without any increase inweight. Moreover, this construction provides a convenient method ofadjusting the weight of the racket by simply modifying the wall gaugethickness of the metal from which the sectional frame member is formed.

Various methods of stringing the racket are applicable in conjunctionwith the approved construction described above. Thus the strings mayeither be connected directly to the frame or through auxiliaryattachment means, in various simple and effective Ways.

According to FIGS. 7 and 8, the webportion 6 of the member 1 and spaceror brace member 2 are perforated at spaced locations and eyelets 15having rounded edges are inserted through the perforations 14. In thiscase both walls of the web portion 6 are preferably contiguous. Thestrings 16 are passed through the eyelets and it will readily beunderstood that with this arrangement the strings sustain no sharpbends; moreover the string portions 164: lying alongside the frame arepositioned within the grooves 8 and are thus protected from damage e.g.when the outer periphery of the frame strikes or rubs against thesurface of a tennis court. If desired, the eyelets may be dispensed withand the holes 14 formed with suitably rounded edges.

Embodiments using intermediate string attaching means will now bedescribed. In FIGS. 9 and 10, the strings 16 are attached to the frameby way of a coil or helix 17 of piano wire or the like, wound about theframe member. This method of stringing the racket also derivesconsiderable benefit from the puarticular type of frame member usedaccording to the invention.

Firstly, the winding of the coil is facilitated in regard to the factthat the pitch of the coil should, as will be understood, be variedalong the length of the frame memher in order to achieve the requisitespacing between the strings in the different parts of the frame. Thisproblem of correct pitch variation is solved according to the inventionby using during the stringing process, a template 18 contoured so as tobe insertable into the outer groove 8 of the frame member, the templatebeing formed along its outer surface with spaced notches 19 adapted toreceive the turns of the coil 17. The template may remain in place inthe finished racket or may be removed after the stringing operation.

In any case tests have shown that after the coil has been properly woundand tightened about the frame member, provided the coil is made fromsufliciently stiff wire, the turns of the coil will not be liable toslip or turn. The coil can be stretched tight without impedingsubsequent stringing operations since the inner groove 7 in the framemember provides the necessary clearance for threading the strings 16.Moreover, the strings mayv be passed around two adjacent turns whererequired without any tendency to shifting the turns. Furthermore,provided the groove 7 has been suitably dimensioned, the strings will beretained laterally by the heads 5 thereby preventing any warping orshifting of the plane of the strings.

The same general advantages as above are present in cases where thestrings are not directly attached to the coil. Thusin the embodimentsshown in FIGS. 11 and 12, the strings are attached by way of an annulus2! made of spring steel or the like, and formed with castellations orserrations 21 suitably spaced in regard to the prescribed spacing of thestrings 16.

In this case the coil 17 can be very conveniently wound about the framemember and the annulus 20. For this purpose the annulus 20 is snappedinto the inner groove 7 of the frame where it is retained by itsinherent elasticity without there being any need to provide separateguiding or retaining means therefor. A template such as 18-(-FIGS. 9 and10) may or not be used in this instance as desired. Desirably the ends29a of the annulus are bent outwards towards the frame member, one ofthe outbent ends being preferably inserted into a small anchoring recessZilb formed in the inner side of theframe member.

The coil is threaded through the notches 21a defined in the apices ofthe serrations. The strings 16 are passed across the bases 21b of theserrations and under the coil as shown in FIG. 12. In this case also thegroove 7 provides the necessary clearance for the passing of the stringswhile the beads act to guide and retain the annulus thereby preventingthe strings from shifting and vibrating in use. Such a string assemblyis found to possess an especially desirable elasticity owing to theelasticity of the annulus 20.

FIG. 13 illustrates some modified means of attaching the coil 17 to theframe member 1. In this case the coil wire is so Wound as to presentcrossed'loops 17a to provide half-hitches as at 17b. The strings 16 arepassed over the half-hitches and are thereby retained at the requisitespacings while preventing sharp bends in the string. The strings areretained in position by the beads 5 of the frame. The spacing betweenthe spans of string 16 may if desired be increased by providing thehalf-hitch with a round turn as shown at 17c. A template is is desirablyprovided in the outer groove 8 of the frame member.

In accordance with a further form shown in FIG. 14 spaced rings 22 maybe provided around the frame member for attaching the strings to theframe. As shown in FIG. 14 the rings 22, eg metallic and of round crosssection, are retained in the requisite spaced relation by means oftubular spacers 23 of appropriately selected lengths and formed withnotches 24 to provide clearance for the strings 16. The strings areguided in the groove 7 which moreover enables the strings to be threadedthrough the rings without having to impart an intricate shape to therings. Where desired the strings may be passed round one or more spacedrings.

In FIGS. and 16 the tubular spacer 23 are omitted and castellated spacerstrips 25 received in the outer groove 8 of the frame member are usedinstead.

According to FIG. 17 the ring 26 is formed with an inward projection orboss 27 in its side positioned outwardly of the racket which bossengages into the outer groove 8 of the frame member. The string 16 isretained in and guided by groove 7.

The rings 26 may be spaced by means of spacers in the form of spots 23of solder or plastic resin (e.g. Araldite) deposited within the groove 8between the bosses of the rings to maintain the prescribed spacingsbetween them.

Various other modifications and alternative will occur to those familiarwith the art within the scope of the present invention. In the claimsthe term tennis racket should be construed in a broad sense so as toinclude rackets for games other than lawn-tennis, e.g. squash andbadminton.

What I claim is:

1. A tennis racket comprising a frame shaped from a frame member ofuniform cross sectional contour including a pair of spaced bead portionsprojecting from opposite sides of the racket frame and aninterconnecting web portion defining a pair of longitudinal groovesrespectively extending along the inner and outer peripheries of theframe; spacer means located within the outer one of said grooves andproviding gaps at predetermined spacings along the outer periphery ofthe frame; string attachment means providing a plurality of loopspassing around said frame member and within said gaps; strings engagingsaid loops and strung across the frame, portions of said stringsextending into the inner said groove and a handle connected to saidframe.

2. A racket as claimed in claim 1, wherein said string attachment meanscomprise a wire coiled around said frame members and having turnsengaging said gaps.

3. A racket as claimed in claim 1 wherein said string attachment meanscomprise a Wire Wound around said frame member into loops providinghalf-hitches and respectively engaging said gaps, said strings beingpassed over said half-hitches.

4. -A racket as claimed in claim 1 wherein said spacer means comprise anarcuate template strip member having one edge inserted in said outer oneof said grooves and provided in its outwardly directed surface withnotches defining said gaps.

5. A racket as claimed in claim 1 wherein said string attachment meanscomprise rings surrounding the frame member and engaging said gaps.

6. A racket as claimed in claim 5 wherein said spacer means comprisespacer members positioned in said outer one of said grooves intermediatesaid rings and provided at their ends with notches wherein said ringsengage.

7. A racket as claimed in claim 5 wherein said rings are provided with aprojection engaging said outer one of said grooves.

8. A racket as claimed in claim 7 wherein said spacer means comprisespots deposited within said groove intermediate said projections of saidrings.

References (Iited in the file of this patent UNITED STATES PATENTS1,452,803 iHarris Apr. 24, 1923 1,502,845 Blache n July 29, 19241,750,727 Norton Mar. 18, 1930 2,171,223 Robinson Aug. 29, 19392,456,023 Rosenbalm Dec. 14, 1948 FOREIGN PATENTS 14,397 Great Britain1909 855,902 France Feb. 26, 1940

1. A TENNIS RACKET COMPRISING A FRAME SHAPED FROM A FRAME MEMBER OFUNIFORM CROSS SECTIONAL CONTOUR INCLUDING A PAIR OF SPACED BEAD PORTIONSPROJECTING FROM OPPOSITE SIDES OF THE RACKET FRAME AND ANINTERCONNECTING WEB PORTION DEFINING A PAIR OF LONGITUDINAL GROOVESRESPECTIVELY EXTENDING ALONG THE INNER AND OUTER PERIPHERIES OF THEFRAME; SPACER MEANS LOCATED WITHIN THE OUTER ONE OF SAID GROOVES ANDPROVIDING GAPS AT PREDETERMINED SPACINGS ALONG THE OUTER PERIPHERY OFTHE FRAME; STRING ATTACHMENT MEANS PROVIDING A PLURALITY OF LOOPSPASSING AROUND SAID FRAME MEMBER AND WITHIN SAID GAPS; STRINGS ENGAGINGSAID LOOPS AND STRUNG ACROSS THE FRAME, PORTIONS OF SAID STRINGSEXTENDING INTO THE INNER SAID GROOVE AND A HANDLE CONNECTED TO SAIDFRAME.